A compensation method and device based on a large-length calibration device

Abstract

The present application relates to a kind of compensation method and compensation device based on large length calibration device, the compensation method includes: setting the compensation reference point of large length calibration device;Real-time measurement value L of large length calibration device is obtained using the following formula: L=L laser +dz*R XY +dy*R XZ ;Wherein, L laser It is the real-time display value of laser interferometer, dy and dz are the distance between the target of laser interferometer and the target of the calibrated equipment in Y direction and Z direction respectively, R XY And R XZ It is the angle error of movable stage of large length calibration device relative to compensation reference point;The measurement value L is used to compensate the measurement value of the calibrated equipment.The present application solves the problems of complex compensation process, low efficiency and high cost in the prior art of large length calibration device.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of compensation of large length calibration device, and particularly relates to a compensation method and a compensation device based on a large length calibration device. BACKGROUND

[0002] The large length calibration device is a precision industrial mobile coordinate measurement calibration system taking laser wavelength as a measurement reference, mainly composed of a high-precision laser measurement system, a high-precision linear guide rail group system, a precision environmental parameter measurement compensation system, a precision air floating workbench system, a mobile driving system and a central control system. Under the action of various system control software and various special measurement software, the central control system realizes automatic measurement and calibration of the calibrated equipment (for example, a laser tracker, a laser range finder, a laser interferometer, a standard steel tape, etc.) through real-time correction evaluation of the guide rail Abbe error and precision environmental parameter measurement compensation, and through various auxiliary fixtures and software packages.

[0003] At present, the large length calibration device generally adopts three laser interferometers to measure length synchronously, compensates for the difference of laser position readings of the large length calibration device at different positions based on the principle of Abbe error, and fixes the positions of the three laser interferometers, so that the target of the calibrated equipment (for example, a laser tracker) is also fixed, thereby realizing Abbe error compensation.

[0004] This compensation method needs three laser interferometers, has high cost, and because only the position error is measured, the positions of the three laser interferometers must be relatively fixed, the compensation calculation process is complex, which leads to low efficiency, and if the optical path of the calibrated device or the target occupies the laser path of the laser interferometer, the position of the calibrated device needs to be adjusted, and the calculation method will also bring certain error due to the change of the position. SUMMARY

[0005] In order to solve the above technical problems, one of the present application provides a compensation method based on a large length calibration device, which solves the problems of complex compensation process, low efficiency and high cost of multiple laser interferometers in the large length calibration device in the prior art.

[0006] To achieve the above technical purposes, the present application proposes the following technical solutions to solve them:

[0007] The present application relates to a compensation method based on a large length calibration device, characterized in that it comprises:

[0008] S1: setting a compensation reference point of the large length calibration device, wherein the length direction of the large length calibration device is defined as X direction;

[0009] S2: acquiring a measurement value L of the large length calibration device in real time by using the following formula:

[0010] L= Llaser + dz * R XY + dy * R XZ ;

[0011] wherein, L laser is a real-time display value of the laser interferometer, dy and dz are distances between a target of the laser interferometer and a target of the calibrated device in Y direction and Z direction respectively, R XY and R XZ are angle errors of the movable stage of the large length calibration device relative to the compensation reference point;

[0012] S3: compensating the calibrated device by using the measurement value L;

[0013] wherein, the target of the laser interferometer and the target of the calibrated device are both placed on the movable stage.

[0014] The compensation method based on the large length calibration device provided in the application has the following advantages and beneficial effects:

[0015] (1) The error compensation is realized by combining the large length calibration device and one laser interferometer, the number of laser interferometers required is small, the investment cost is reduced, and the angle error, the display value of the laser interferometer and the distance between the laser interferometer and the calibrated device in Y direction and Z direction are used to realize the error compensation of the calibrated device, the compensation mode is simple, and high-efficiency compensation is realized.

[0016] (2) The target of the laser interferometer is placed at any position on the movable stage, and there is no need to fix the position, so that the compensation flexibility is improved.

[0017] In some embodiments of the application, the angle errors R XY and R XZ are obtained, and specifically, the following steps are performed:

[0018] The length of the large length calibration device is divided into multiple steps;

[0019] Before S2, a set of angle errors {R XY , R XZ} of each step relative to the compensation reference point are obtained by using the laser interferometer, and multiple sets of angle errors corresponding to the multiple steps are formed;

[0020] In the compensation process, based on the current position of the movable stage and the angle errors corresponding to each step, the interpolation method is used to obtain the angle errors {R XY , R XZ} of the position of the movable stage between the steps relative to the compensation reference point.

[0021] In some embodiments of the present application, before S2, the movable stage is moved to a plurality of step distances, and the angle error R of each step distance relative to the compensation reference point is obtained XY and R XZ ;

[0022] Then, the movable stage is placed at the compensation reference point, and the movable stage is moved to a plurality of step distances again, and the angle error R of each step distance relative to the compensation reference point is obtained XY and R XZ .

[0023] In some embodiments of the present application, S3: the measured value L2 is used to compensate the calibrated device, specifically:

[0024] S31: the error E=L-L is obtained, where L is the measured value displayed by the calibrated device in real time;

[0025] S32: the measured value of the calibrated device is compensated by using the error E.

[0026] The present application also relates to a compensation device based on a large-length calibration device, which is used to compensate the measured value of a calibrated device, comprising:

[0027] a laser interferometer, the target of which and the target of the calibrated device are both placed on the movable stage of the large-length calibration device, and the distance between the target of the laser interferometer and the target of the calibrated device in Y direction and Z direction is dy and dz respectively;

[0028] a processing unit configured to obtain the measured value L of the large-length calibration device by using the following formula:

[0029] L= L laser + dz*R XY + dy*R XZ ;

[0030] wherein L laser is the value displayed by the laser interferometer in real time, and R XY and R XZ are the angle errors of the movable stage of the large-length calibration device relative to the compensation reference point;

[0031] a compensation unit configured to compensate the calibrated device by using the measured value L.

[0032] In some embodiments of the present application, before the compensation process, the laser interferometer obtains a set of angle errors {R XY , R XZform a plurality of sets of angle errors corresponding to a plurality of steps, wherein the length of the long length calibration device is divided into a plurality of steps;

[0033] The compensation device further comprises:

[0034] a storage unit for storing the sets of angle errors.

[0035] In some embodiments of the present application, before compensation, the movable stage is moved to a plurality of steps, and the laser interferometer obtains angle errors R XY and R XZ at each step relative to the compensation reference point.

[0036] Then, the movable stage is moved to the compensation reference point, and the movable stage is moved to a plurality of steps again, and the laser interferometer obtains angle errors R XY and R XZ at each step relative to the compensation reference point.

[0037] In some embodiments of the present application, the compensation device further comprises:

[0038] a calculation unit, which, during compensation, calculates angle errors {R XY , R XZ} of the movable stage at positions between steps relative to the compensation reference point based on the current position of the movable stage and the angle errors stored in the storage unit.

[0039] In some embodiments of the present application, the calibrated device is compensated by using the measured value L, specifically:

[0040] obtaining an error E=L 示值 -L, L 示值 of the calibrated device, wherein L is the measured value of the calibrated device in real time.

[0041] compensating the measured value of the calibrated device by using the error E.

[0042] Other features and advantages of the present application will become more apparent after reading the specific embodiments of the present application in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the description of the embodiments of the present application or the prior art. Obviously, the drawings described below are some embodiments of the present application, and those skilled in the art can obtain other drawings according to these drawings without any creative effort.

[0044] Figure 1 A flow chart of the compensation method based on the large-length calibration device according to the present application is shown in the figure.

[0045] Figure 2 A schematic diagram of the geometric error of the large-length calibration device in the X direction. DETAILED DESCRIPTION

[0046] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments of the present application.

[0047] Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application. In the description of the present application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only used to facilitate the description of the present application and simplify the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0048] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrally connected. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances. In the description of the above embodiments, specific features, structures, materials or characteristics can be combined in any one or more embodiments or examples in a suitable manner.

[0049] The terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more features. In the description of the present application, unless otherwise specified, the meaning of "multiple" is two or more.

[0050] In view of the problems that the compensation process is complex and the investment cost is high when the large-length calibration device compensates the measurement value of the calibrated device in the prior art, the present application provides a compensation method based on a large-length calibration device.

[0051] Figure 1 A flow chart of the compensation method based on the large-length calibration device is shown.

[0052] It should be noted that the compensation method involved in the present application is realized by using a compensation device, therefore, as follows, the compensation method shown in the present application will be described in combination with the compensation device. Figure 1 It should be noted that the compensation method involved in the present application is realized by using a compensation device, therefore, as follows, the compensation method shown in the present application will be described in combination with the compensation device.

[0053] S1: Set the compensation reference point of the large-length calibration device, wherein the length direction of the large-length calibration device is defined as the X direction.

[0054] Set the starting position in the large-length calibration device as the compensation reference point, which is the zero point of compensation.

[0055] The present application relates to the compensation of the measurement value of the large-length calibration device when measuring the calibrated device in a single-axis direction.

[0056] Although the length direction of the large-length calibration device is defined as the X direction in S1, it can also be defined as the Y direction or the Z direction instead, and the compensation method is the same.

[0057] In the present application, the length direction of the large-length calibration device is set as the X direction, the horizontal direction perpendicular to the X direction is defined as the Y direction, and the vertical direction perpendicular to the X direction is defined as the Z direction.

[0058] S2: Real-time obtain the measurement value L of the large-length calibration device by using the following formula: L = L laser + dz*R XY +dy*R XZ .

[0059] In the present application, the measurement value of the calibrated device is compensated by using the measurement value L of the large-length calibration device.

[0060] The compensation device includes a laser interferometer, a processing unit and a compensation unit.

[0061] The laser interferometer can cooperate with various refractive mirrors, reflecting mirrors and the like to perform linear position, speed, angle, flatness, straightness, parallelism and perpendicularity measurement work, and can be used as a correction work of a precision tool machine or a measuring instrument.

[0062] The calibrated device can be, for example, a laser tracker, a laser interferometer and the like.

[0063] In the present application, the target of the laser interferometer (for example, a reflecting mirror in the motion direction) and the target of the calibrated device (for example, when the calibrated device is a laser tracker, the target is a laser tracker reflecting mirror (i.e. a target mirror)) are placed on the moving table of the large-length calibration device.

[0064] Generally, the angle error values of all point positions on the movable table of the large length calibration device can be considered to be the same, and there is no difference, so the target of the laser interferometer can be arranged at any position on the movable table to achieve the same measurement value, and thus the arrangement position of the target of the laser interferometer can be flexibly set.

[0065] At present, large-scale calibration devices (for example, the large length calibration device involved in the present application) include sliding components (for example, the movable table of the large length calibration device in the present application) running on linear guides, and in fact, the linear guides on which the sliding components run are not perfectly straight, and machining errors and other kinds of errors (such as errors of the transmission system) cause the sliding components to have six-directional movements: three linear displacement movements and three rotational angle movements. According to mechanics, each sliding component has six degrees of freedom when it moves along its axis, which are generally called geometric errors.

[0066] Each geometric error is expressed by the error value at each independent position reached by the sliding component on the axis when it moves along the axis.

[0067] In the present application, the large length calibration device only considers single-axis sliding, so the movements in the Y direction and the Z direction can be approximately considered to be zero, and only the relevant errors in the X direction are considered.

[0068] As described above, referring to Figure 2 , the three linear displacement movements represent the X-direction linear displacement movement L XX when moving in the X direction, the Y-direction linear displacement movement L XY when moving in the X direction, and the Z-direction linear displacement movement L XZ when moving in the X direction; the three rotational angle movements represent the X-direction rotational angle movement R XX when moving in the X direction, the Y-direction rotational angle movement R XY when moving in the X direction, and the Z-direction rotational angle movement R XZ when moving in the X direction.

[0069] Generally, if the movements in the Y direction and the Z direction are not considered, the X-direction error Ex in the X-direction length can be calculated according to the following formula.

[0070] Ex = L XX + R XY * dz + R XZ * dy. (1)

[0071] As follows, the case of the error of the measurement center position caused when the positive rotational angle R XY is generated when moving in the X direction will be described.

[0072] In the case that the movable stage has no geometric error, the movable stage and the target height are located at the Xs and Zs positions in the X and Z directions, in which case, R XY = 0, the error of the measurement center position is not affected by R XY .

[0073] In the case that the movable stage has geometric error, the geometric error changes the actual running route of the movable stage, in which case, R XY ≠ 0, the target height deviation (i.e. dz) rotates in the YZ plane, causing the position error of the measurement center position along the Y and Z axes.

[0074] Therefore, the X-direction error of the measurement center position caused by R XY is:

[0075] Ex' = R XY * dz.

[0076] Similarly, the error of the measurement center position caused by the positive rotation angle R XZ when moving in the X direction can be analyzed.

[0077] In the case that the movable stage has no geometric error, R XZ = 0, the error of the measurement center position is not affected by R XZ .

[0078] In the case that the movable stage has geometric error, the geometric error changes the actual running route of the movable stage, in which case, R XZ ≠ 0, the target distance deviation in the Y direction (i.e. dy) rotates in the YZ plane, causing the position error of the measurement center position along the Y and Z axes.

[0079] Therefore, the X-direction error of the measurement center position caused by R XZ is:

[0080] Ex'' = R XZ * dy.

[0081] Thus, the X-direction error of the measurement center position caused by the rotation angles R XY and R XZ is dz*R XY + dy*R XZ .

[0082] Therefore, the X-direction error Ex in the X-direction length can be calculated according to the above formula (1).

[0083] In the present application, the measured value of the measured calibration device is compensated based on the measurement principle as described above.

[0084] In the present application, L in formula (1) above is obtained by a laser interferometer XX , R XY and R XZ .

[0085] wherein L XX denotes the position reading displayed by the laser interferometer (i.e. L laser as described above), and R XY and R XZ are the angular errors of the current position of the movable stage relative to the compensation reference point obtained by the laser interferometer.

[0086] Therefore, in the compensation process, as long as L laser , the angular error R XY and R XZ are obtained, the distance L actually measured by the large length calibration device can be obtained.

[0087] That is, L = L laser + dz*R XY + dy*R XZ . (2)

[0088] wherein dz denotes the height deviation of the target in the Z direction, and dy denotes the distance deviation of the target in the Y direction.

[0089] As described above, the target of the laser interferometer and the target of the device to be calibrated are both placed on the movable stage, and therefore the distance dy in the Y direction and the distance dz in the Z direction between the target of the laser interferometer and the target of the device to be calibrated can be measured by a ruler, for example.

[0090] This distance dy and dz is a fixed parameter after the target of the laser interferometer and the target of the device to be calibrated are set, and does not change during the measurement process, and therefore this distance dy and dz should be measured before the measurement of the device to be calibrated.

[0091] In the compensation process of the large length calibration device, the distance L is obtained by formula (2) above based on the obtained L laser , R XY and R XZ , and the existing parameters dy and dz.

[0092] The calculation as described above is implemented by a processing unit in the compensation device.

[0093] In the present application, in order to facilitate calibration, the length of the large length calibration device is divided into multiple steps.

[0094] Each step is equal, for example, the step length step is 200 mm.

[0095] Thus, before compensation calibration, a set of angle errors {R XY , R XZ} of each step distance relative to the compensation reference point is measured using a laser interferometer, so that a plurality of sets of angle errors are obtained for a plurality of step distances.

[0096] The obtained plurality of sets of angle errors can be stored in a storage unit in advance.

[0097] In the compensation calibration process, the angle error at the current position between adjacent step distances can be obtained according to an interpolation method based on the angle errors at the adjacent step distances called.

[0098] For example, the angle errors at adjacent step distances n and n+1 are En and En+1 respectively, when the movable stage is located at position m (n < m < n+1), the angle error Em at the position m is calculated as follows:

[0099] Em = En + (En+1 – En) * (m-n) / Step.

[0100] Thus, the angle error between step distances is obtained.

[0101] As described above, En, En+1 and Em can refer to R XY , or R XZ .

[0102] That is, R XY（m） = R XY(n) + (R XY(n+1) – R XY(n) ) * (m-n) / Step.

[0103] R XZ（m） = R XZ(n) + (R XZ(n+1) – R XZ(n) ) * (m-n) / Step.

[0104] R XY（m） refers to the angle error R XY at position m, R XY(n) refers to the angle error R XY at step distance n, R XY(n+1) refers to the angle error R XY at step distance n+1, and m-n refers to the X-direction distance between step distance m and step distance n.

[0105] R XZ（m） refers to the angle error R XZ at position m, R XZ(n) refers to the angle error R XZ at step distance n, R XZ(n+1) refers to the angle error R at step distance n+1.XZ m-n refers to the X direction distance between the step m and the step n.

[0106] Thus, based on the stored multiple sets of angle deviations at the steps, it is convenient to call during the compensation calibration.

[0107] The angle error between the steps is obtained in real time during the compensation calibration, and is calculated by the calculation unit.

[0108] In the present application, in order to ensure the accuracy of obtaining the angle error at each step, before the compensation calibration, the movable table is moved from the compensation reference point to each step, and the laser interferometer is used to obtain the angle error R XY and R XZ at each step relative to the compensation reference point, for example, the angle error R XY is obtained.

[0109] Then, the movable table is reset to the compensation reference point, and the movable table is moved to each step again, and the laser interferometer is used to obtain the other one of the angle error R XY and R XZ at each step relative to the compensation reference point, for example, the angle error R XZ is obtained.

[0110] S3: Compensate the measurement value of the calibrated device with the measurement value L.

[0111] Such compensation is realized by a compensation unit in the compensation device.

[0112] The specific compensation method is described as follows.

[0113] S31: Obtain the error E=L 示值 -L of the calibrated device, L 示值 is the measurement value displayed in real time by the calibrated device.

[0114] As described in S2, the large length calibration device has obtained the measurement value L of the large length calibration device in combination with the laser interferometer.

[0115] Thus, the error E=L 示值 -L of the calibrated device is obtained, L 示值 is the measurement value displayed in real time by the calibrated device, and the measurement value of the calibrated device is calibrated by using the large length calibration device.

[0116] S32: Compensate the measurement value of the calibrated device with the error E.

[0117] The error E is the calibration compensation value of the large length calibration device to the calibrated device, and the calibration compensation value is used to realize the calibration compensation of the calibrated device.

[0118] That is, when the calibrated device is used to measure, the compensation value is considered so that the calibrated device measures more accurately.

[0119] Therefore, the compensation method and the compensation device can compensate the measurement value of the calibrated device by using one laser interferometer, and the laser interferometer can be arranged flexibly because the target of the laser interferometer is located on the movable stage.

[0120] In addition, the parameters for calculating the measurement value L of the large length calibration device involve the fixed parameters dy, dz and the angle error at each step distance determined in advance, so the compensation method can be applied to the compensation calibration of various calibrated devices, has high universality, and is simple and efficient.

[0121] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that the technical solutions recorded in the foregoing examples can still be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A compensation method based on a large length calibration device, characterized in that, The compensation method comprises the following steps: S1: setting a compensation reference point of the large-length calibration device, wherein a length direction of the large-length calibration device is defined as an X direction; S2: acquiring a measurement value L of the large-length calibration device in real time by using the following formula: L = L laser + dz * R XY + dy * R XZ ; wherein, L laser is the real-time display value of the laser interferometer, dy and dz are the distances between the target of the laser interferometer and the target of the calibrated equipment in Y direction and Z direction respectively, R XY and R XZ are the compensation angle errors of the current position of the movable table of the large-length calibration device relative to the compensation reference point, the laser interferometer pre-acquires a set of angle errors at each step relative to the compensation reference point, forming a plurality of sets of angle errors corresponding to a plurality of steps, wherein the length of the large-length calibration device is divided into a plurality of steps; the compensation angle error is specifically: When the current position of the movable platform is located at each step distance, the angle error corresponding to each step distance is taken as the compensation angle error; When the current position of the movable platform is located at a position between adjacent step distances, the angle error of the position between the adjacent step distances relative to the compensation reference point is acquired by using an interpolation method based on the current position of the movable platform and the angle error corresponding to each step distance, and is taken as the compensation angle error; S3: compensating a measurement value of a calibrated device by using the measurement value L, comprising the following steps: S31: obtaining the error E = L of the calibrated device 示值 - L, L 示值 displaying the measurement value in real time for the calibrated device; S32: compensating the measurement value of the calibrated device by using the error E; The target of the laser interferometer and the target of the calibrated device are both arranged on the movable platform of the large-length calibration device.

2. The compensation method according to claim 1, wherein Before S2, the movable platform is moved to a plurality of step distances, and one of the angle errors relative to the compensation reference point at each step distance is acquired; Then, the movable platform is arranged at the compensation reference point, and the movable platform is moved to the plurality of step distances again, and the other of the angle errors relative to the compensation reference point at each step distance is acquired.

3. A compensation device based on a large length calibration device for compensating a measurement value of a device under calibration, a compensation reference point of the large length calibration device is set, a length direction of the large length calibration device is defined as an X direction, characterized in that, The compensation device comprises: a laser interferometer, a target of the laser interferometer and a target of the calibrated device are both arranged on a movable platform of the large-length calibration device, and distances between the target of the laser interferometer and the target of the calibrated device in Y and Z directions are dy and dz respectively; a processing unit configured to acquire a measurement value L of the large-length calibration device by using the following formula: L = L laser + dz * R XY + dy * R XZ ; Wherein, L laser is the real-time display value of the laser interferometer, R XY and R XZ is the compensation angle error of the current position of the movable table of the large length calibration device relative to the compensation reference point, the laser interferometer pre-acquires a set of angle errors at each step distance relative to the compensation reference point, forming a plurality of sets of angle errors corresponding to a plurality of step distances, wherein the length of the large length calibration device is divided into a plurality of step distances; The compensation angle error is specifically: When the current position of the movable platform is located at each step distance, the angle error corresponding to each step distance is taken as the compensation angle error; When the current position of the movable platform is located at a position between adjacent step distances, the angle error of the position between the adjacent step distances relative to the compensation reference point is acquired by using an interpolation method based on the current position of the movable platform and the angle error corresponding to each step distance, and is taken as the compensation angle error; a compensation unit configured to compensate a measurement value of a calibrated device by using the measurement value L, comprising: acquiring an error E = L 示值 - L, L 示值 displaying a measurement value in real time for the calibrated device; compensating the measurement value of the calibrated device by using the error E.

4. The compensation device of claim 3, wherein The compensation device further comprises: a storage unit configured to store the plurality of sets of angle errors corresponding to the plurality of step distances.

5. The compensation device according to claim 4, wherein Before compensation, the movable platform is moved to a plurality of step distances, and the laser interferometer acquires one of the angle errors relative to the compensation reference point at each step distance; Then, the movable platform is moved to the compensation reference point, and the movable platform is moved to the plurality of step distances again, and the laser interferometer acquires the other of the angle errors relative to the compensation reference point at each step distance.

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